Gaarst

What? Is it not obvious that through our endless complaining and criticism of whatever Squad does we mean KSP is one of the best games we've ever played?

@MalevolentNinja I'll do a few measurements on spread angles whenever I have time (so either tomorrow or next week-end) to try to put some numbers behind it. I don't know if larger numbers of symmetry than stock are affected by this, maybe the bonus is only coded for up to 8 parachutes, that'd be an interesting thing to look at.

Wheels physics are still a bit wonky, even after the numerous patches of 1.1 and 1.2. While it has gotten better overall, some weird things still happen, especially with the non-steerable fixed gear (you're "lowriding" as soon as you touch the runway). To help with this, you can try messing with the spring and damper settings (as you already did) which my help, or you can try to land more gently which again may or not help. There are probably some fixed made by the community, but I can't remember any off the top of my head (I know @GoSlash27 was pretty involved in this in 1.1, so he might be able to help you better than I did).

Done!

This thread is copied straight from another thread I wrote in KSP Discussion. I'm opening this one here to make it easier to find for people who would need it (thank Slashy for this suggestion).

Thank you for your explanation. I don't usually build spaceplanes (or anything build to sustain supersonic speeds for that matter) but that is always good to know. My plane achieves 12.8 at sea level and flying at ~75m/s, so yeah it definitely is easier to get a good L/D ratio at lower speeds. The fact you can't reach real life L/D ratios at subsonic speeds is a bit sad, I actually like flying slowly and just watch the scene, guess I'll have to stick to my 8h autonomy "powered glider"

Title. I got to 12 with a high aspect ratio design (plane was very similar to a glider, only with engines) and that is pretty terrible compared to real world planes. Am I just that bad at building planes or are all planes less efficient in KSP? (You can view L/D ratio by enabling the Aero GUI in the Cheats menu)

Which is exactly what I found in my measurements, I think you understood it the wrong way around (I just realised that I never worded that finding correctly so I'm correcting this now)

I wouldn't be surprised that "some Unity excuse" forced the developers to implement interference only for symmetry with parachutes unable to interact with the ones that were placed independently. EDIT: John FX said it better than I did I don't recall ever reading anything like this in the recent patch notes, so either this is very old and I somehow never noticed, or it's indeed a bug (or I just have a terrible memory).

Do you use FAR or other mods changing the atmosphere? Because according to my numbers, your craft is twice heavier than it should to fall at this speed. I'd like a confirmation before re-doing everything from the start.

I haven't tried messing with the spread angle (because I kinda forgot this even existed) so I don't know whether or not this affects the drag caused by the parachutes. I don't think it's a bug. The results from both radial chutes (regular and drogue) seem very consistent with a 1.5th power law. I wouldn't be surprised that in real life some interactions between the parachutes could make it that the air disturbance extends further than the physical surface of the parachutes, but I'm not really sure.

Yeah I just wrote aEarth because I started with Earth but it works for any planet.

You could calculate them pretty easily. Just work out the half orbital period of the transfer orbit: that's the time you will need to reach your target planet. In this time the planet will have moved a fraction of its orbit that you can express as an angle. The Hohmann transfer angle is then just 180° minus that angle (because you want to meet the planet at 180° relative to your departing point). Signs shouldn't be a problem since everything orbits in the same direction. Similarly you don't need to worry about plane inclination since it doesn't change the orbital period of your transfer orbit (but you want to include it in your dV calculation). Things get a little more complicated with eccentric orbits because the transfer orbit is not the same depending on when you do your transfer. Using this method I get 44.6° for Mars from Earth, hopefully it's correct (needs to be checked). Edit: the formula is: angle = 180° * ( 1 - ( (aEarth/aDestination + 1) / 2)3/2) aEarth and aDestination are the SMAs of Earth and your destination respectively, using AU you can take aEarth = 1

What a helpful, meaningful topic. You want something done you do it yourself before asking that "someone" should "really" do it.

The point of a Wiki is that this "someone" can be anyone, including you.

AFAIK the parachute calculator thingy is not updated since a long time so I've bothered doing this stuff. If you wonder how many chutes you need to slow down a craft to a given speed then take a look: I've done a few measurements and have derived a few formulas for parachutes mechanics. First, let's start with a bit of physics before the maths. The terminal velocity of an object in air is obtained by equating drag and gravitational pull and is: , v is the terminal velocity of the object, m its mass, g the gravitational acceleration, ρ is the density of the air, Cx is the drag coefficient and A is the effective area. In practice, Cx and A are always grouped together since dissociating one from the other is hard, especially in KSP. From now on, g will be taken to be 9.81 m/s2 and ρ to be the air density ASL on Kerbin (about 1.116 kg.m-3), so the results will only be valid at the surface of Kerbin, but adapting them to other bodies would be simple as you would just need to change these two parameters. For a single chute we can then write the terminal velocity as: , defining the constant B as (the greater B is, the faster the body will fall). B is a constant that is valid for a given parachute part and on the surface of Kerbin, it has a different value for each parachute in the game that can be found by reversing the equation above: Mk16 chute: B = 0.029 Mk2R radial chute: B = 0.039 Mk16XL chute: B = 0.020 Mk25 drogue chute: B = 1.099 Mk12R radial drogue chute: B = 1.065 The above is valid for a single chute. When you consider multiple chutes, the only part that changed in B is the parameter CxA which depends on the surface of parachutes: you can consider several chutes to be a single larger chute. When trying stuff in game, you find that the stack chutes behave nicely when adding chutes: 2 chutes means CxA is twice greater, B is twice smaller and your craft falls √2 times slower. Radial chutes are annoying. As is turns out, when you place several radial chutes in symmetry their area does not scale linearly, ie: 2 in chutes symmetry doesn't mean B becomes 2*B, instead you find that B becomes about 21.5*B. The total area of several radial chutes placed in symmetry scales with their number to the power 1.5. This means that 2 radial chutes placed in symmetry are more efficient than 2 identical parachutes placed separately (same thing for more chutes). Note that if you place several radial chutes not in symmetry (placing them separately) they add up linearly, like stack chutes. For several chutes, the equation to find the terminal velocity of a vessel becomes: . B is the "parachute constant" from earlier, unchanged even for several parachutes, m is the mass of the vessel, n is the number of parachutes and α is a number that depends on the type of chute used: it is 1 for stack chutes and radial chutes placed independently, and it is 1.5 for radial chutes placed in symmetry (to account for the non-linear increase). If you have two different types of chutes, your terminal velocity is then: (the summation is done this way because math), and so on for more types of chutes: . By rearranging the equation, you can solve other parachute related problems: The maximal mass that can be slowed to under a given speed by a given number and type of parachutes is: , or if you have several types of parachutes: The number of parachutes of a given type needed to slow a given mass to a given speed is: I am not physically (and mentally) capable or writing web pages or making mods so if anyone wants to take these stupid equations and make something useful out of them, feel free to. EDIT: I did a few measurements for the other bodies of the Kerbal system, to help people for interplanetary parachute landings. Use the constant B for another body with the same equations above, nothing else changes. Kerbin Duna Eve Laythe Mk16 0.029 0.079 0.009 0.036 Mk2-R (radial) 0.039 0.105 0.012 0.047 Mk16-XL 0.020 0.054 0.006 0.024 Mk25 (drogue) 1.099 2.967 0.340 1.331 Mk12-R (radial drogue) 1.065 2.877 0.330 1.291 All measurements were taken ASL (~370m for Duna) so your craft will fall a little faster than predicted if you're higher up. If someone feels like getting values for the Sun or Jool go ahead.

If your staging is done correctly, the dV of your upper stages should not depend on what's below. Maybe pictures of your craft could help.

What Tex_NL said: go fast and high. This plane can go around the planet in a bit over an hour, and has enough fuel to make it to Kerbaikonur and back without the drop-tanks. Replace the cabins by fuel tanks or structural fuselage if you need even greater range.

Here you go: https://en.wikipedia.org/wiki/Tsiolkovsky_rocket_equation Have fun!

Understand this how you want.

Subassemblies already exist. Click the arrow at the very top-left in the Editor to bring the "advanced editor" and click on the green rocket icon to show the Subassemblies tab.

Fuel cells.

Don't want to break everything so spend a few months not updating; Waiting for mods to update, especially for that one mod which is obviously dead, but who-knows-it-might-get-updated-soon; Waiting for RSS/RF configs to update; Install all mods and remove half of them because they don't work anymore; Find new mods; Move my own configs to the new version (takes a lot of time because I never remember which are the ones I wrote); Write new configs because the old ones don't work anymore; Play new version. I do also spend more time outside the game than inside, but I spend way less time managing my mods than I used to, now it's mostly managing my main save (planning missions, crew rotas, transfers...)

Drag and lift are functions of density (and speed squared).

Yeah, I pretty much agree on that.